1
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Rajanathan R, Pedersen TM, Guldbrandsen HO, Olesen LF, Thomsen MB, Bøtker HE, Matchkov VV. Augmented Ouabain-Induced Vascular Response Reduces Cardiac Efficiency in Mice with Migraine-Associated Mutation in the Na +, K +-ATPase α 2-Isoform. Biomedicines 2023; 11:biomedicines11020344. [PMID: 36830881 PMCID: PMC9953359 DOI: 10.3390/biomedicines11020344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/22/2023] [Accepted: 01/23/2023] [Indexed: 01/27/2023] Open
Abstract
Heterozygous mice (α2+/G301R mice) for the migraine-associated mutation (G301R) in the Na+,K+-ATPase α2-isoform have decreased expression of cardiovascular α2-isoform. The α2+/G301R mice exhibit a pro-contractile vascular phenotype associated with decreased left ventricular ejection fraction. However, the integrated functional cardiovascular consequences of this phenotype remain to be addressed in vivo. We hypothesized that the vascular response to α2-isoform-specific inhibition of the Na+,K+-ATPase by ouabain is augmented in α2+/G301R mice leading to reduced cardiac efficiency. Thus, we aimed to assess the functional contribution of the α2-isoform to in vivo cardiovascular function of wild-type (WT) and α2+/G301R mice. Blood pressure, stroke volume, heart rate, total peripheral resistance, arterial dP/dt, and systolic time intervals were assessed in anesthetized WT and α2+/G301R mice. To address rate-dependent cardiac changes, cardiovascular variables were compared before and after intraperitoneal injection of ouabain (1.5 mg/kg) or vehicle during atrial pacing. The α2+/G301R mice showed an enhanced ouabain-induced increase in total peripheral resistance associated with reduced efficiency of systolic development compared to WT. When the hearts were paced, ouabain reduced stroke volume in α2+/G301R mice. In conclusion, the ouabain-induced vascular response was augmented in α2+/G301R mice with consequent suppression of cardiac function.
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Affiliation(s)
- Rajkumar Rajanathan
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
- Correspondence:
| | | | | | | | - Morten B. Thomsen
- Department of Biomedical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark
| | - Hans Erik Bøtker
- Department of Cardiology, Aarhus University Hospital, 8000 Aarhus, Denmark
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2
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Wang Q, Li N, Guo X, Huo B, Li R, Feng X, Fang Z, Zhu XH, Wang Y, Yi X, Wei X, Jiang DS. Comprehensive analysis identified a reduction in ATP1A2 mediated by ARID3A in abdominal aortic aneurysm. J Cell Mol Med 2022; 26:2866-2880. [PMID: 35441443 PMCID: PMC9097831 DOI: 10.1111/jcmm.17301] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 03/02/2022] [Accepted: 03/18/2022] [Indexed: 12/17/2022] Open
Abstract
Abdominal aortic aneurysm (AAA) is characterized by abdominal aorta dilatation and progressive structural impairment and is usually an asymptomatic and potentially lethal disease with a risk of rupture. To investigate the underlying mechanisms of AAA initiation and progression, seven AAA datasets related to human and mice were downloaded from the GEO database and reanalysed in the present study. After comprehensive bioinformatics analysis, we identified the enriched pathways associated with inflammation responses, vascular smooth muscle cell (VSMC) phenotype switching and cytokine secretion in AAA. Most importantly, we identified ATPase Na+/K+ transporting subunit alpha 2 (ATP1A2) as a key gene that was significantly decreased in AAA samples of both human and mice; meanwhile, its reduction mainly occurred in VSMCs of the aorta; this finding was validated by immunostaining and Western blot in human and mouse AAA samples. Furthermore, we explored the potential upstream transcription factors (TFs) that regulate ATP1A2 expression. We found that the TF AT‐rich interaction domain 3A (ARID3A) bound the promoter of ATP1A2 to suppress its expression. Our present study identified the ARID3A‐ATP1A2 axis as a novel pathway in the pathological processes of AAA, further elucidating the molecular mechanism of AAA and providing potential therapeutic targets for AAA.
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Affiliation(s)
- Qunhui Wang
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Na Li
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xian Guo
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Bo Huo
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Rui Li
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xin Feng
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Zemin Fang
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xue-Hai Zhu
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.,Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation, Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan, Hubei, China
| | - Yixiang Wang
- Clinical medical College, Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Xin Yi
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Xiang Wei
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.,Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation, Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan, Hubei, China
| | - Ding-Sheng Jiang
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.,Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation, Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan, Hubei, China
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3
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Obara K, Kawaguchi A, Inaba R, Kawakita M, Yamaguchi R, Yamashita H, Xu K, Ou G, Yamaki F, Yoshioka K, Tanaka Y. Docosahexaenoic Acid and Eicosapentaenoic Acid Inhibit the Contractile Responses of the Guinea Pig Lower Gastrointestinal Tract. Biol Pharm Bull 2021; 44:1129-1139. [PMID: 34334498 DOI: 10.1248/bpb.b21-00362] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are n-3 polyunsaturated fatty acids (PUFAs), and are abundant in fish oil. These n-3 PUFAs have been reported to improve the lower gastrointestinal (LGI) disorders such as ulcerative colitis and Crohn's disease through their anti-inflammatory effects. However, there are few studies on the effect of n-3 PUFAs on motility of the LGI tract, such as the ileum and colon, the parts frequently affected by these inflammatory disorders. To elucidate the effects of DHA and EPA on the LGI tract motility, we performed comparative evaluation of their effects and linoleic acid (LA), an n-6 PUFA, on contractions in the ileal and colonic longitudinal smooth muscles (LSMs) isolated from guinea pigs. In the ileal and colonic LSMs, DHA and EPA (3 × 10-5 M each) significantly inhibited contractions induced by acetylcholine (ACh), histamine, and prostaglandin (PG) F2α (vs. control), and these effects are stronger than that of LA (3 × 10-5 M). In the colonic LSMs, DHA and EPA also significantly inhibited contractions induced by PGD2 (vs. control). In addition, DHA and EPA significantly inhibited CaCl2-induced ileal and colonic LSM contractions in Ca2+-free 80 mM-KCl solution (vs. control). Any ileal and colonic LSM contractions induced by ACh, histamine, PGF2α, and CaCl2 were completely suppressed by verapamil (10-5 M), a voltage-gated/dependent Ca2+ channel (VGCC/VDCC) inhibitor. These findings suggest that DHA and EPA could improve the abnormal contractile functions of the LGI tract associated with inflammatory diseases, partly through inhibition of VGCC/VDCC-dependent ileal and colonic LSM contractions.
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Affiliation(s)
- Keisuke Obara
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Ayana Kawaguchi
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Rikako Inaba
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Mirai Kawakita
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Rika Yamaguchi
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Haruna Yamashita
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Keyue Xu
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Guanghan Ou
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Fumiko Yamaki
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University.,Department of Pharmacy, Faculty of Pharmacy, Musashino University
| | - Kento Yoshioka
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Yoshio Tanaka
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
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4
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Wang Y, Zhang J, Wier WG, Chen L, Blaustein MP. NO-induced vasodilation correlates directly with BP in smooth muscle-Na/Ca exchanger-1-engineered mice: elevated BP does not attenuate endothelial function. Am J Physiol Heart Circ Physiol 2021; 320:H221-H237. [PMID: 33124883 PMCID: PMC7847073 DOI: 10.1152/ajpheart.00487.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 10/26/2020] [Accepted: 10/26/2020] [Indexed: 12/29/2022]
Abstract
Arterial smooth muscle Na+/Ca2+ exchanger-1 (SM-NCX1) promotes vasoconstriction or vasodilation by mediating, respectively, Ca2+ influx or efflux. In vivo, SM-NCX1 mediates net Ca2+ influx to help maintain myogenic tone (MT) and neuronally activated constriction. SM-NCX1-TG (overexpressing transgenic) mice have increased MT and mean blood pressure (MBP; +13.5 mmHg); SM-NCX1-KO (knockout) mice have reduced MT and MBP (-11.1 mmHg). Endothelium-dependent vasodilation (EDV) is often impaired in hypertension. We tested whether genetically engineered SM-NCX1 expression and consequent BP changes similarly alter EDV. Isolated, pressurized mesenteric resistance arteries with MT from SM-NCX1-TG and conditional SM-NCX1-KO mice, and femoral arteries in vivo from TG mice were studied. Acetylcholine (ACh)-dilated TG arteries with MT slightly more than control or KO arteries, implying that SM-NCX1 overexpression does not impair EDV. In preconstricted KO, but not TG mouse arteries, however, ACh- and bradykinin-triggered vasodilation was markedly attenuated. To circumvent the endothelium, phenylephrine-constricted resistance arteries were tested with Na-nitroprusside [SNP; nitric oxide (NO) donor] and cGMP. This endothelium-independent vasodilation was augmented in TG but attenuated in KO arteries that lack NCX1-mediated Ca2+ clearance. Baseline cytosolic Ca2+ ([Ca2+]cyt) was elevated in TG femoral arteries in vivo, supporting the high BP; furthermore, SNP-triggered [Ca2+]cyt decline and vasodilation were augmented as NO and cGMP promote myocyte polarization thereby enhancing NCX1-mediated Ca2+ efflux. The TG mouse data indicate that BP elevation does not attenuate endothelium-dependent vasodilation. Thus, in essential hypertension and many models the endothelial impairment that supports the hypertension apparently is not triggered by BP elevation but by extravascular mechanisms.NEW & NOTEWORTHY Endothelium-dependent, ACh-induced vasodilation (EDV) is attenuated, and arterial myocyte Na+/Ca2+ exchangers (NCX1) are upregulated in many forms of hypertension. Surprisingly, mildly hypertensive smooth muscle-specific (SM)-NCX1 transgenic mice exhibited modestly enhanced EDV and augmented endothelium-independent vasodilation (EIV). Conversely, mildly hypotensive SM-NCX1-knockout mice had greatly attenuated EIV. These adaptations help compensate for NCX1 expression-induced alterations in cytosolic Ca2+ and blood pressure (BP) and belie the view that elevated BP, itself, causes the endothelial dysregulation in hypertension.
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Affiliation(s)
- Youhua Wang
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
- Department of Physical Education, Shaanxi Normal University, Xi'an, Shaanxi, China
| | - Jin Zhang
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - W Gil Wier
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Ling Chen
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Mordecai P Blaustein
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
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5
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A Review of Endothelium-Dependent and -Independent Vasodilation Induced by Phytochemicals in Isolated Rat Aorta. Animals (Basel) 2019; 9:ani9090623. [PMID: 31470540 PMCID: PMC6769919 DOI: 10.3390/ani9090623] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/17/2019] [Accepted: 08/21/2019] [Indexed: 12/27/2022] Open
Abstract
Simple Summary Cardiovascular diseases are the leading cause of death worldwide, so the investigation of new therapeutic tools is a priority for their prevention and treatment. This review shows the relevant contribution of the isolated rat aorta as an in vitro experimental model to validate the therapeutic potential of phytochemicals, mainly those present in plants traditionally used in folk medicine to relieve hypertension. The results of the assays carried out in this model show that a variety of plant extracts and their isolated compounds produce vasodilation, which may explain their use, especially to treat hypertension. Abstract This review discusses the contribution of the use of the isolated rat aorta (IRA) as a model for the evaluation of extracts and metabolites produced by plants with a vasodilator effect in animals. This model continues to be a valuable approach for the search and development of new phytochemicals consumed as medicinal plants or foods. In most cases, the sources of phytochemicals have been used in folk medicine to treat ailments that include hypertension. In this model, the endothelium is emphasized as a key component that modulates the vessel contractility, and therefore the basal tone and blood pressure. Based on the functional nature of the model, we focused on studies that determined the endothelium-dependent and -independent vasodilatory activity of phytochemicals. We describe the mechanisms that account for aorta contraction and relaxation, and subsequently show the vasoactive effect of a series of phytochemicals acting as vasodilators and its endothelium dependence. We highlight information regarding the cardiovascular benefits of phytochemicals, especially their potential antihypertensive effect. On this basis, we discuss the advantages of the IRA as a predictive model to support the research and development of new drugs that may be of help in the prevention and treatment of cardiovascular diseases, the number one cause of death worldwide.
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6
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Zhang J, Wang Y, Chen L, Wier WG, Blaustein MP. Na +/Ca 2+ exchanger overexpression in smooth muscle augments cytosolic Ca 2+ in femoral arteries of living mice. Am J Physiol Heart Circ Physiol 2019; 316:H298-H310. [PMID: 30461304 PMCID: PMC6397384 DOI: 10.1152/ajpheart.00185.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 11/05/2018] [Accepted: 11/15/2018] [Indexed: 11/22/2022]
Abstract
Plasma membrane Na+/Ca2+ exchanger-1 (NCX1) helps regulate the cytosolic Ca2+ concentration ([Ca2+]CYT) in arterial myocytes. NCX1 mediates both Ca2+ entry and exit and tends to promote net Ca2+ entry in partially constricted arteries. Mean blood pressure (telemetry) is elevated by ≈10 mmHg in transgenic (TG) mice that overexpress NCX1 specifically in smooth muscle. We tested the hypothesis that NCX1 overexpression mediates Ca2+ gain and elevated [Ca2+]CYT in exposed femoral arteries that also express the Ca2+ biosensor exogenous myosin light chain kinase. [Ca2+]CYT and the NCX1-dependent (SEA0400-sensitive) component, ≈15% of total basal constriction in controls, were increased in TG arteries, but constrictions to phenylephrine and ANG II were comparable in TG and control arteries. Normalized phenylephrine dose-response curves and constriction to 30 and 300 ng/kg iv ANG II were virtually identical in control and TG arteries. ANG II-evoked constrictions, superimposed on elevated basal tone, accounted for the larger blood pressure responses to ANG II in TG arteries. TG and control mouse arteries fit the same pCa-constriction relationship over a wide range of pCa (≈125-500 nM). Vasodilation to acetylcholine, normalized to passive diameter, was also comparable in TG and control arteries, implying normal endothelial function. TG artery Na+ nitroprusside (nitric oxide donor)-induced dilations were, however, shifted to lower Na+ nitroprusside concentrations, indicating that TG myocyte vasodilator mechanisms were augmented. Maximum arterial dilation was comparable in TG and control mice, although passive diameter was ≈6-7% smaller in TG mice. The changes in TG arteries were apparently largely functional rather than structural, despite the congenital hypertension. NEW & NOTEWORTHY Smooth muscle Na+/Ca2+ exchanger-1 transgene overexpression (TG mice) increases femoral artery basal cytosolic Ca2+ concentration ([Ca2+]CYT) and tone in vivo and raises blood pressure. Arterial constriction to phenylephrine and angiotensin II are normal but superimposed on the augmented basal [Ca2+]CYT and tone (constriction) in TG mouse arteries. Similar effects in resistance arteries would explain the elevated blood pressure. Acetylcholine-induced vasodilation is unimpaired, implying a normal endothelium, but TG arteries are hypersensitive to sodium nitroprusside.
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Affiliation(s)
- Jin Zhang
- Department of Physiology, University of Maryland School of Medicine , Baltimore, Maryland
| | - Youhua Wang
- Department of Physiology, University of Maryland School of Medicine , Baltimore, Maryland
- Department of Physical Education, Shaanxi Normal University , Xi'an, Shaanxi , China
| | - Ling Chen
- Department of Physiology, University of Maryland School of Medicine , Baltimore, Maryland
- Department of Medicine, University of Maryland School of Medicine , Baltimore, Maryland
| | - W Gil Wier
- Department of Physiology, University of Maryland School of Medicine , Baltimore, Maryland
| | - Mordecai P Blaustein
- Department of Physiology, University of Maryland School of Medicine , Baltimore, Maryland
- Department of Medicine, University of Maryland School of Medicine , Baltimore, Maryland
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7
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Stafford N, Wilson C, Oceandy D, Neyses L, Cartwright EJ. The Plasma Membrane Calcium ATPases and Their Role as Major New Players in Human Disease. Physiol Rev 2017; 97:1089-1125. [PMID: 28566538 DOI: 10.1152/physrev.00028.2016] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 01/20/2017] [Accepted: 01/23/2017] [Indexed: 02/07/2023] Open
Abstract
The Ca2+ extrusion function of the four mammalian isoforms of the plasma membrane calcium ATPases (PMCAs) is well established. There is also ever-increasing detail known of their roles in global and local Ca2+ homeostasis and intracellular Ca2+ signaling in a wide variety of cell types and tissues. It is becoming clear that the spatiotemporal patterns of expression of the PMCAs and the fact that their abundances and relative expression levels vary from cell type to cell type both reflect and impact on their specific functions in these cells. Over recent years it has become increasingly apparent that these genes have potentially significant roles in human health and disease, with PMCAs1-4 being associated with cardiovascular diseases, deafness, autism, ataxia, adenoma, and malarial resistance. This review will bring together evidence of the variety of tissue-specific functions of PMCAs and will highlight the roles these genes play in regulating normal physiological functions and the considerable impact the genes have on human disease.
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Affiliation(s)
- Nicholas Stafford
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Claire Wilson
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Delvac Oceandy
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Ludwig Neyses
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Elizabeth J Cartwright
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
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8
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Nguy L, Shubbar E, Jernås M, Nookaew I, Lundgren J, Olsson B, Nilsson H, Guron G. Adenine-induced chronic renal failure in rats decreases aortic relaxation rate and alters expression of proteins involved in vascular smooth muscle calcium handling. Acta Physiol (Oxf) 2016; 218:250-264. [PMID: 27239807 DOI: 10.1111/apha.12724] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Revised: 11/24/2015] [Accepted: 05/27/2016] [Indexed: 12/23/2022]
Abstract
AIM Rats with adenine-induced chronic renal failure (A-CRF) develop a reduced rate of relaxation of the thoracic aorta. The aim of this study was to elucidate the mechanisms underlying this abnormality. METHODS Male Sprague Dawley rats received either chow containing adenine or were pair-fed with normal chow (controls). After 8-14 weeks, arterial function was analysed ex vivo using wire myography and the expression of proteins involved in vascular smooth muscle excitation-contraction coupling in the thoracic aorta was analysed. RESULTS The rate of relaxation following washout of KCl was reduced in A-CRF rats vs. controls in the thoracic aorta (P < 0.01), abdominal aorta (P < 0.05), and common carotid artery (P < 0.05), but not in the common femoral artery. Relaxation rates of thoracic aortas increased (P < 0.01), but were not normalized, in response to washout of KCl with Ca2+ -free buffer. Microarray and qRT-PCR analyses of genes involved in excitation-contraction coupling identified 10 genes, which showed significantly altered expression in A-CRF thoracic aortas. At the protein level, the α2 subunit of the Na,K-ATPase (P < 0.001) and SERCA2 (P < 0.05) was significantly downregulated, whereas stromal interaction molecule 1 and calsequestrin-1 and calsequestrin-2 were significantly upregulated (P < 0.05). CONCLUSIONS Rats with A-CRF show a marked alteration in relaxation of larger conduit arteries localized proximal to the common femoral artery. This abnormality may be caused by reduced cytosolic Ca2+ clearance in vascular smooth muscle cells secondary to dysregulation of proteins crucially involved in this process.
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Affiliation(s)
- L. Nguy
- Department of Molecular and Clinical Medicine/Nephrology; Institute of Medicine; Gothenburg Sweden
- Department of Physiology; Institute of Neuroscience and Physiology; Gothenburg Sweden
| | - E. Shubbar
- Department of Molecular and Clinical Medicine/Nephrology; Institute of Medicine; Gothenburg Sweden
| | - M. Jernås
- Department of Internal Medicine; Institute of Medicine; Gothenburg Sweden
| | - I. Nookaew
- Department of Chemical and Biological Engineering; Chalmers University of Technology; Gothenburg Sweden
- Comparative Genomics Group; Biosciences Division; Oak Ridge National Laboratory; Oak Ridge TN USA
| | - J. Lundgren
- Department of Molecular and Clinical Medicine/Nephrology; Institute of Medicine; Gothenburg Sweden
| | - B. Olsson
- Department of Psychiatry and Neurochemistry; Institute of Neuroscience and Physiology; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
| | - H. Nilsson
- Department of Physiology; Institute of Neuroscience and Physiology; Gothenburg Sweden
| | - G. Guron
- Department of Molecular and Clinical Medicine/Nephrology; Institute of Medicine; Gothenburg Sweden
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9
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Blaustein MP, Chen L, Hamlyn JM, Leenen FHH, Lingrel JB, Wier WG, Zhang J. Pivotal role of α2 Na + pumps and their high affinity ouabain binding site in cardiovascular health and disease. J Physiol 2016; 594:6079-6103. [PMID: 27350568 DOI: 10.1113/jp272419] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 06/18/2016] [Indexed: 12/13/2022] Open
Abstract
Reduced smooth muscle (SM)-specific α2 Na+ pump expression elevates basal blood pressure (BP) and increases BP sensitivity to angiotensin II (Ang II) and dietary NaCl, whilst SM-α2 overexpression lowers basal BP and decreases Ang II/salt sensitivity. Prolonged ouabain infusion induces hypertension in rodents, and ouabain-resistant mutation of the α2 ouabain binding site (α2R/R mice) confers resistance to several forms of hypertension. Pressure overload-induced heart hypertrophy and failure are attenuated in cardio-specific α2 knockout, cardio-specific α2 overexpression and α2R/R mice. We propose a unifying hypothesis that reconciles these apparently disparate findings: brain mechanisms, activated by Ang II and high NaCl, regulate sympathetic drive and a novel neurohumoral pathway mediated by both brain and circulating endogenous ouabain (EO). Circulating EO modulates ouabain-sensitive α2 Na+ pump activity and Ca2+ transporter expression and, via Na+ /Ca2+ exchange, Ca2+ homeostasis. This regulates sensitivity to sympathetic activity, Ca2+ signalling and arterial and cardiac contraction.
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Affiliation(s)
- Mordecai P Blaustein
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA. .,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
| | - Ling Chen
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - John M Hamlyn
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Frans H H Leenen
- Hypertension Unit, University of Ottawa Heart Institute, Ottawa, ON, Canada, K1Y 4W7
| | - Jerry B Lingrel
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267-0524, USA
| | - W Gil Wier
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Jin Zhang
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
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10
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The role of Na+, K+-ATPase in the hypoxic vasoconstriction in isolated rat basilar artery. Vascul Pharmacol 2016; 81:53-60. [DOI: 10.1016/j.vph.2016.02.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 02/18/2016] [Accepted: 02/22/2016] [Indexed: 11/18/2022]
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11
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Shattock MJ, Ottolia M, Bers DM, Blaustein MP, Boguslavskyi A, Bossuyt J, Bridge JHB, Chen-Izu Y, Clancy CE, Edwards A, Goldhaber J, Kaplan J, Lingrel JB, Pavlovic D, Philipson K, Sipido KR, Xie ZJ. Na+/Ca2+ exchange and Na+/K+-ATPase in the heart. J Physiol 2015; 593:1361-82. [PMID: 25772291 PMCID: PMC4376416 DOI: 10.1113/jphysiol.2014.282319] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 10/30/2014] [Indexed: 12/17/2022] Open
Abstract
This paper is the third in a series of reviews published in this issue resulting from the University of California Davis Cardiovascular Symposium 2014: Systems approach to understanding cardiac excitation–contraction coupling and arrhythmias: Na+ channel and Na+ transport. The goal of the symposium was to bring together experts in the field to discuss points of consensus and controversy on the topic of sodium in the heart. The present review focuses on cardiac Na+/Ca2+ exchange (NCX) and Na+/K+-ATPase (NKA). While the relevance of Ca2+ homeostasis in cardiac function has been extensively investigated, the role of Na+ regulation in shaping heart function is often overlooked. Small changes in the cytoplasmic Na+ content have multiple effects on the heart by influencing intracellular Ca2+ and pH levels thereby modulating heart contractility. Therefore it is essential for heart cells to maintain Na+ homeostasis. Among the proteins that accomplish this task are the Na+/Ca2+ exchanger (NCX) and the Na+/K+ pump (NKA). By transporting three Na+ ions into the cytoplasm in exchange for one Ca2+ moved out, NCX is one of the main Na+ influx mechanisms in cardiomyocytes. Acting in the opposite direction, NKA moves Na+ ions from the cytoplasm to the extracellular space against their gradient by utilizing the energy released from ATP hydrolysis. A fine balance between these two processes controls the net amount of intracellular Na+ and aberrations in either of these two systems can have a large impact on cardiac contractility. Due to the relevant role of these two proteins in Na+ homeostasis, the emphasis of this review is on recent developments regarding the cardiac Na+/Ca2+ exchanger (NCX1) and Na+/K+ pump and the controversies that still persist in the field.
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Affiliation(s)
- Michael J Shattock
- King's College London BHF Centre of Excellence, The Rayne Institute, St Thomas' Hospital, London, SE1 7EH, UK
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12
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Chen L, Song H, Wang Y, Lee JC, Kotlikoff MI, Pritchard TJ, Paul RJ, Zhang J, Blaustein MP. Arterial α2-Na+ pump expression influences blood pressure: lessons from novel, genetically engineered smooth muscle-specific α2 mice. Am J Physiol Heart Circ Physiol 2015. [PMID: 26209057 DOI: 10.1152/ajpheart.00430.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Arterial myocytes express α1-catalytic subunit isoform Na(+) pumps (75-80% of total), which are ouabain resistant in rodents, and high ouabain affinity α2-Na(+) pumps. Mice with globally reduced α2-pumps (but not α1-pumps), mice with mutant ouabain-resistant α2-pumps, and mice with a smooth muscle (SM)-specific α2-transgene (α2 (SM-Tg)) that induces overexpression all have altered blood pressure (BP) phenotypes. We generated α2 (SM-DN) mice with SM-specific α2 (not α1) reduction (>50%) using nonfunctional dominant negative (DN) α2. We compared α2 (SM-DN) and α2 (SM-Tg) mice to controls to determine how arterial SM α2-pumps affect vasoconstriction and BP. α2 (SM-DN) mice had elevated basal mean BP (mean BP by telemetry: 117 ± 4 vs. 106 ± 1 mmHg, n = 7/7, P < 0.01) and enhanced BP responses to chronic ANG II infusion (240 ng·kg(-1)·min(-1)) and high (6%) NaCl. Several arterial Ca(2+) transporters, including Na(+)/Ca(2+) exchanger 1 (NCX1) and sarcoplasmic reticulum and plasma membrane Ca(2+) pumps [sarco(endo)plasmic reticulum Ca(2+)-ATPase 2 (SERCA2) and plasma membrane Ca(2+)-ATPase 1 (PMCA1)], were also reduced (>50%). α2 (SM-DN) mouse isolated small arteries had reduced myogenic reactivity, perhaps because of reduced Ca(2+) transporter expression. In contrast, α2 (SM-Tg) mouse aortas overexpressed α2 (>2-fold), NCX1, SERCA2, and PMCA1 (43). α2 (SM-Tg) mice had reduced basal mean BP (104 ± 1 vs. 109 ± 2 mmHg, n = 15/9, P < 0.02) and attenuated BP responses to chronic ANG II (300-400 ng·kg(-1)·min(-1)) with or without 2% NaCl but normal myogenic reactivity. NCX1 expression was inversely related to basal BP in SM-α2 engineered mice but was directly related in SM-NCX1 engineered mice. NCX1, which usually mediates arterial Ca(2+) entry, and α2-Na(+) pumps colocalize at plasma membrane-sarcoplasmic reticulum junctions and functionally couple via the local Na(+) gradient to help regulate cell Ca(2+). Altered Ca(2+) transporter expression in SM-α2 engineered mice apparently compensates to minimize Ca(2+) overload (α2 (SM-DN)) or depletion (α2 (SM-Tg)) and attenuate BP changes. In contrast, Ca(2+) transporter upregulation, observed in many rodent hypertension models, should enhance Ca(2+) entry and signaling and contribute significantly to BP elevation.
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Affiliation(s)
- Ling Chen
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland; Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Hong Song
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Youhua Wang
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Jane C Lee
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Michael I Kotlikoff
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Tracy J Pritchard
- College of Nursing, College of Medicine, University of Cincinnati, Cincinnati, Ohio; and
| | - Richard J Paul
- Department of Molecular and Cell Physiology, College of Medicine, University of Cincinnati, Cincinnati, Ohio
| | - Jin Zhang
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Mordecai P Blaustein
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland; Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland;
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13
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Olschewski A, Papp R, Nagaraj C, Olschewski H. Ion channels and transporters as therapeutic targets in the pulmonary circulation. Pharmacol Ther 2014; 144:349-68. [PMID: 25108211 DOI: 10.1016/j.pharmthera.2014.08.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 07/22/2014] [Indexed: 10/24/2022]
Abstract
Pulmonary circulation is a low pressure, low resistance, high flow system. The low resting vascular tone is maintained by the concerted action of ion channels, exchangers and pumps. Under physiological as well as pathophysiological conditions, they are targets of locally secreted or circulating vasodilators and/or vasoconstrictors, leading to changes in expression or to posttranslational modifications. Both structural changes in the pulmonary arteries and a sustained increase in pulmonary vascular tone result in pulmonary vascular remodeling contributing to morbidity and mortality in pediatric and adult patients. There is increasing evidence demonstrating the pivotal role of ion channels such as K(+) and Cl(-) or transient receptor potential channels in different cell types which are thought to play a key role in vasoconstrictive remodeling. This review focuses on ion channels, exchangers and pumps in the pulmonary circulation and summarizes their putative pathophysiological as well as therapeutic role in pulmonary vascular remodeling. A better understanding of the mechanisms of their actions may allow for the development of new options for attenuating acute and chronic pulmonary vasoconstriction and remodeling treating the devastating disease pulmonary hypertension.
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Affiliation(s)
- Andrea Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Experimental Anesthesiology, Department of Anesthesia and Intensive Care Medicine, Medical University of Graz, Austria.
| | - Rita Papp
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Chandran Nagaraj
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Horst Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Department of Internal Medicine, Division of Pulmonology, Medical University of Graz, Austria
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14
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Ewart MA, Kennedy S, Macmillan D, Raja ALN, Watt IM, Currie S. Altered vascular smooth muscle function in the ApoE knockout mouse during the progression of atherosclerosis. Atherosclerosis 2014; 234:154-61. [PMID: 24657385 PMCID: PMC3997800 DOI: 10.1016/j.atherosclerosis.2014.02.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 01/29/2014] [Accepted: 02/18/2014] [Indexed: 02/07/2023]
Abstract
Objectives Relaxation of vascular smooth muscle (VSM) requires re-uptake of cytosolic Ca2+ into the sarcoplasmic reticulum (SR) via the Sarco/Endoplasmic Reticulum Ca2+ ATPase (SERCA), or extrusion via the Plasma Membrane Ca2+ ATPase (PMCA) or sodium Ca2+ exchanger (NCX). Peroxynitrite, a reactive species formed in vascular inflammatory diseases, upregulates SERCA activity to induce relaxation but, chronically, can contribute to atherogenesis and altered vascular function by escalating endoplasmic reticulum stress. Our objectives were to determine if peroxynitrite-induced relaxation and Ca2+ handling processes within vascular smooth muscle cells were altered as atherosclerosis develops. Methods Aortae from control and ApoE−/− mice were studied histologically, functionally and for protein expression levels of SERCA and PMCA. Ca2+ responses were assessed in dissociated aortic smooth muscle cells in the presence and absence of extracellular Ca2+. Results Relaxation to peroxynitrite was concentration-dependent and endothelium-independent. The abilities of the SERCA blocker thapsigargin and the PMCA inhibitor carboxyeosin to block this relaxation were altered during fat feeding and plaque progression. SERCA levels were progressively reduced, while PMCA expression was upregulated. In ApoE−/− VSM cells, increases in cytosolic Ca2+ [Ca2+]c in response to SERCA blockade were reduced, while SERCA-independent Ca2+ clearance was faster compared to control. Conclusion As atherosclerosis develops in the ApoE−/− mouse, expression and function of Ca2+ handling proteins are altered. Up-regulation of Ca2+ removal via PMCA may offer a potential compensatory mechanism to help normalise the dysfunctional relaxation observed during disease progression. Expression and function of SERCA and PMCA are temporally altered in ApoE−/− VSM. TG-induced increases in [Ca2+]c were reduced in ApoE−/− aortic SM cells. Ca2+ extrusion is upregulated in isolated ApoE−/− aortic SM cells.
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Affiliation(s)
- Marie-Ann Ewart
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, G12 8QQ, UK.
| | - Simon Kennedy
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, G12 8QQ, UK
| | - Debbi Macmillan
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow G4 0NR, UK
| | - Abhirami L N Raja
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, G12 8QQ, UK
| | - Ian M Watt
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, G12 8QQ, UK
| | - Susan Currie
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow G4 0NR, UK
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15
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Mechanically induced intercellular calcium communication in confined endothelial structures. Biomaterials 2013; 34:2049-56. [PMID: 23267827 DOI: 10.1016/j.biomaterials.2012.11.060] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 11/29/2012] [Indexed: 12/12/2022]
Abstract
Calcium signaling in the diverse vascular structures is regulated by a wide range of mechanical and biochemical factors to maintain essential physiological functions of the vasculature. To properly transmit information, the intercellular calcium communication mechanism must be robust against various conditions in the cellular microenvironment. Using plasma lithography geometric confinement, we investigate mechanically induced calcium wave propagation in networks of human umbilical vein endothelial cells organized. Endothelial cell networks with confined architectures were stimulated at the single cell level, including using capacitive force probes. Calcium wave propagation in the network was observed using fluorescence calcium imaging. We show that mechanically induced calcium signaling in the endothelial networks is dynamically regulated against a wide range of probing forces and repeated stimulations. The calcium wave is able to propagate consistently in various dimensions from monolayers to individual cell chains, and in different topologies from linear patterns to cell junctions. Our results reveal that calcium signaling provides a robust mechanism for cell-cell communication in networks of endothelial cells despite the diversity of the microenvironmental inputs and complexity of vascular structures.
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16
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Zhang J. New insights into the contribution of arterial NCX to the regulation of myogenic tone and blood pressure. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 961:329-43. [PMID: 23224892 DOI: 10.1007/978-1-4614-4756-6_28] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Plasma membrane protein Na(+)/Ca(2+) exchanger (NCX) in vascular smooth muscle (VSM) cells plays an important role in intracellular Ca(2+) homeostasis, Ca(2+) signaling, and arterial contractility. Recent evidence in intact animals reveals that VSM NCX type 1 (NCX1) is importantly involved in the control of arterial blood pressure (BP) in the normal state and in hypertension. Increased expression of vascular NCX1 has been implicated in human primary pulmonary hypertension and several salt-dependent hypertensive animal models. Our aim is to determine the molecular and physiological mechanisms by which vascular NCX influences vasoconstriction and BP normally and in salt-dependent hypertension. Here, we describe the relative contribution of VSM NCX1 to Ca(2+) signaling and arterial contraction, including recent data from transgenic mice (NCX1(smTg/Tg), overexpressors; NCX1(sm-/-), knockouts) that has begun to elucidate the specific contributions of NCX to BP regulation. Arterial contraction and BP correlate with the level of NCX1 expression in smooth muscle: NCX1(sm-/-) mice have decreased arterial myogenic tone (MT), vasoconstriction, and low BP. NCX1(smTg/Tg) mice have high BP and are more sensitive to salt; their arteries exhibit upregulated transient receptor potential canonical channel 6 (TRPC6) protein, increased MT, and vasoconstriction. These observations suggest that NCX is a key component of certain distinct signaling pathways that activate VSM contraction in response to stretch (i.e., myogenic response) and to activation of certain G-protein-coupled receptors. Arterial NCX expression and mechanisms that control the local (sub-plasma membrane) Na(+) gradient, including cation-selective receptor-operated channels containing TRPC6, regulate arterial Ca(2+) and constriction, and thus BP.
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Affiliation(s)
- Jin Zhang
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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17
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Linde CI, Antos LK, Golovina VA, Blaustein MP. Nanomolar ouabain increases NCX1 expression and enhances Ca2+ signaling in human arterial myocytes: a mechanism that links salt to increased vascular resistance? Am J Physiol Heart Circ Physiol 2012; 303:H784-94. [PMID: 22842068 DOI: 10.1152/ajpheart.00399.2012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The mechanisms by which NaCl raises blood pressure (BP) in hypertension are unresolved, but much evidence indicates that endogenous ouabain is involved. In rodents, arterial smooth muscle cell (ASMC) Na(+) pumps with an α(2)-catalytic subunit (ouabain EC(50) ≤1.0 nM) are crucial for some hypertension models, even though ≈80% of ASMC Na(+) pumps have an α(1)-subunit (ouabain EC(50) ≈ 5 μM). Human α(1)-Na(+) pumps, however, have high ouabain affinity (EC(50) ≈ 10-20 nM). We used immunoblotting, immunocytochemistry, and Ca(2+) imaging (fura-2) to examine the expression, distribution, and function of Na(+) pump α-subunit isoforms in human arteries and primary cultured human ASMCs (hASMCs). hASMCs express α(1)- and α(2)-Na(+) pumps. Further, α(2)-, but not α(1)-, pumps are confined to plasma membrane microdomains adjacent to sarcoplasmic reticulum (SR), where they colocalize with Na/Ca exchanger-1 (NCX1) and C-type transient receptor potential-6 (receptor-operated channels, ROCs). Prolonged inhibition (72 h) with 100 nM ouabain (blocks nearly all α(1)- and α(2)-pumps) was toxic to most cultured hASMCs. Treatment with 10 nM ouabain (72 h), however, increased NCX1 and sarco(endo)plasmic reticulum Ca(2+)-ATPase expression and augmented ATP (10 μM)-induced SR Ca(2+) release in 0 Ca(2+), ouabain-free media, and Ca(2+) influx after external Ca(2+) restoration. The latter was likely mediated primarily by ROCs and store-operated Ca(2+) channels. These hASMC protein expression and Ca(2+) signaling changes are comparable with previous observations on myocytes isolated from arteries of many rat hypertension models. We conclude that the same structurally and functionally coupled mechanisms (α(2)-Na(+) pumps, NCX1, ROCs, and the SR) regulate Ca(2+) homeostasis and signaling in hASMCs and rodent ASMCs. These ouabain/endogenous ouabain-modulated mechanisms underlie the whole body autoregulation associated with increased vascular resistance and elevation of BP in human, salt-sensitive hypertension.
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Affiliation(s)
- Cristina I Linde
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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18
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Cully TR, Edwards JN, Friedrich O, Stephenson DG, Murphy RM, Launikonis BS. Changes in plasma membrane Ca-ATPase and stromal interacting molecule 1 expression levels for Ca(2+) signaling in dystrophic mdx mouse muscle. Am J Physiol Cell Physiol 2012; 303:C567-76. [PMID: 22785116 DOI: 10.1152/ajpcell.00144.2012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The majority of the skeletal muscle plasma membrane is internalized as part of the tubular (t-) system, forming a standing junction with the sarcoplasmic reticulum (SR) membrane throughout the muscle fiber. This arrangement facilitates not only a rapid and large release of Ca(2+) from the SR for contraction upon excitation of the fiber, but has also direct implications for other interdependent cellular regulators of Ca(2+). The t-system plasma membrane Ca-ATPase (PMCA) and store-operated Ca(2+) entry (SOCE) can also be activated upon release of SR Ca(2+). In muscle, the SR Ca(2+) sensor responsible for rapidly activated SOCE appears to be the stromal interacting molecule 1L (STIM1L) isoform of STIM1 protein, which directly interacts with the Orai1 Ca(2+) channel in the t-system. The common isoform of STIM1 is STIM1S, and it has been shown that STIM1 together with Orai1 in a complex with the partner protein of STIM (POST) reduces the activity of the PMCA. We have previously shown that Orai1 and STIM1 are upregulated in dystrophic mdx mouse muscle, and here we show that STIM1L and PMCA are also upregulated in mdx muscle. Moreover, we show that the ratios of STIM1L to STIM1S in wild-type (WT) and mdx muscle are not different. We also show a greater store-dependent Ca(2+) influx in mdx compared with WT muscle for similar levels of SR Ca(2+) release while normal activation and deactivation properties were maintained. Interestingly, the fiber-averaged ability of WT and mdx muscle to extrude Ca(2+) via PMCA was found to be the same despite differences in PMCA densities. This suggests that there is a close relationship among PMCA, STIM1L, STIM1S, Orai1, and also POST expression in mdx muscle to maintain the same Ca(2+) extrusion properties as in the WT muscle.
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Affiliation(s)
- Tanya R Cully
- School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia
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19
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Matchkov VV, Moeller-Nielsen N, Dam VS, Nourian Z, Briggs Boedtkjer DM, Aalkjaer C. The α2 isoform of the Na,K-pump is important for intercellular communication, agonist-induced contraction, and EDHF-like response in rat mesenteric arteries. Am J Physiol Heart Circ Physiol 2012; 303:H36-46. [PMID: 22561302 DOI: 10.1152/ajpheart.00673.2011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The specific role of different isoforms of the Na,K-pump in the vascular wall is still under debate. We have previously suggested that the α(2) isoform of the Na,K-pump (α(2)), Na(+), Ca(2+)-exchange (NCX), and connexin43 form a regulatory microdomain in smooth muscle cells (SMCs), which controls intercellular communication and contractile properties of the vascular wall. We have tested this hypothesis by downregulating α(2) in cultured SMCs and in small arteries with siRNA in vivo. Intercellular communication was assessed by using membrane capacitance measurements. Arteries transfected in vivo were tested for isometric and isobaric force development in vitro; [Ca(2+)](i) was measured simultaneously. Cultured rat SMCs were well-coupled electrically, but 10 μM ouabain uncoupled them. Downregulation of α(2) reduced electrical coupling between SMCs and made them insensitive to ouabain. Downregulation of α(2) in small arteries was accompanied with significant reduction in NCX expression. Acetylcholine-induced relaxation was not different between the groups, but the endothelium-dependent hyperpolarizing factor-like component of the response was significantly diminished in α(2)-downregulated arteries. Micromolar ouabain reduced in a concentration-dependent manner the amplitude of norepinephrine (NE)-induced vasomotion. Sixty percent of the α(2)-downregulated arteries did not have vasomotion, and vasomotion in the remaining 40% was ouabain insensitive. Although ouabain increased the sensitivity to NE in the control arteries, it had no effect on α(2)-downregulated arteries. In the presence of a low NE concentration the α(2)-downregulated arteries had higher [Ca(2+)](i) and tone. However, the NE EC50 was reduced under isometric conditions, and maximal contraction was reduced under isometric and isobaric conditions. The latter was caused by a reduced Ca(2+)-sensitivity. The α(2)-downregulated arteries also had reduced contraction to vasopressin, whereas the contractile response to high K(+) was not affected. Our results demonstrate the importance of α(2) for intercellular coupling in the vascular wall and its involvement in the regulation of vascular tone.
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Kobayashi Y, Hirawa N, Tabara Y, Muraoka H, Fujita M, Miyazaki N, Fujiwara A, Ichikawa Y, Yamamoto Y, Ichihara N, Saka S, Wakui H, Yoshida SI, Yatsu K, Toya Y, Yasuda G, Kohara K, Kita Y, Takei K, Goshima Y, Ishikawa Y, Ueshima H, Miki T, Umemura S. Mice Lacking Hypertension Candidate Gene ATP2B1 in Vascular Smooth Muscle Cells Show Significant Blood Pressure Elevation. Hypertension 2012; 59:854-60. [DOI: 10.1161/hypertensionaha.110.165068] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Yusuke Kobayashi
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Nobuhito Hirawa
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Yasuharu Tabara
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Hidenori Muraoka
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Megumi Fujita
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Nobuko Miyazaki
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Akira Fujiwara
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Yasuhiro Ichikawa
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Yuichiro Yamamoto
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Naoaki Ichihara
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Sanae Saka
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Hiromichi Wakui
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Shin-ichiro Yoshida
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Keisuke Yatsu
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Yoshiyuki Toya
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Gen Yasuda
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Katsuhiko Kohara
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Yoshikuni Kita
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Kohtaro Takei
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Yoshio Goshima
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Yoshihiro Ishikawa
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Hirotsugu Ueshima
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Tetsuro Miki
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
| | - Satoshi Umemura
- From the Departments of Medical Science and Cardiorenal Medicine (Y.K., M.F., N.M., A.F., N.I., S.S., H.W., S.Y., Y.T., S.U.) and Molecular Pharmacology and Neurobiology (H.M., K.T., Y.G.) and Cardiovascular Research Institute (Y.Ic., Y.Is.), Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension (N.H., Y.Y., K.Y., G.Y.), Yokohama City University Medical Center, Yokohama, Japan; Department of Geriatric Medicine (Y.T., K.K., T.M.), Ehime
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The promise of inhibition of smooth muscle tone as a treatment for erectile dysfunction: where are we now? Int J Impot Res 2011; 24:49-60. [PMID: 21975566 DOI: 10.1038/ijir.2011.49] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ten years ago, the inhibition of Rho kinase by intracavernosal injection of Y-27632 was found to induce an erectile response. This effect did not require activation of nitric oxide-mediated signaling, introducing a novel target pathway for the treatment of erectile dysfunction (ED), with potential added benefit in cases where nitric oxide bioavailability is attenuated (and thus phosphodiesterase type 5 (PDE5) inhibitors are less efficacious). Rho-kinase antagonists are currently being developed and tested for a wide range of potential uses. The inhibition of this calcium-sensitizing pathway results in blood vessel relaxation. It is also possible that blockade of additional smooth muscle contractile signaling mechanisms may have the same effect. In this review, we conducted an extensive search of pertinent literature using PUBMED. We have outlined the various pathways involved in the maintenance of penile smooth muscle tone and discussed the current potential benefit for the pharmacological inhibition of these targets for the treatment of ED.
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Uchida Y, Maezawa Y, Maezawa Y, Uchida Y, Nakamura F. Role of calcium-activated potassium channels in the genesis of 3,4-diaminopyridine-induced periodic contractions in isolated canine coronary artery smooth muscles. J Pharmacol Exp Ther 2011; 338:974-83. [PMID: 21680887 DOI: 10.1124/jpet.111.180687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We found that 3,4-diaminopyridine (3,4-DAP), a voltage-gated potassium channel (K(V)) inhibitor, elicits pH-sensitive periodic contractions (PCs) of coronary smooth muscles. Underlying mechanisms of PCs, however, remained to be elucidated. The present study was performed to examine the roles of ion channels in the genesis of PCs. To determine the electromechanical changes of smooth muscles, isolated coronary arterial rings from beagles were suspended in organ chambers filled with Krebs-Henseleit solution, and 10(-2) M 3,4-DAP was added to elicit PCs. 3,4-DAP caused periodic spike-and-plateau depolarization accompanied by contraction. PCs were not produced when the CaCl(2) concentration in the chamber was ≤ 0.3 × 10(-3) or ≥ 10(-2) M. PCs were eliminated by a CaCl(2) concentration ≥ 5 × 10(-3) M or by lowering pH below 7.20 with HCl and recovered by the addition of iberiotoxin or charybdotoxin, which inhibit large-conductance calcium-activated potassium channels (K(Ca)), or by elevating pH above 7.35 with NaOH. PCs, as well as the spike-and-plateau depolarization, were eliminated by nifedipine, which inhibits L-type voltage-gated calcium channels (Ca(V)). Influx of Ca(2+) through L-type Ca(V), which was opened because closing of K(Ca), secondary to 3,4-DAP-induced closing of K(V), resulted in contraction; the intracellular Ca(2+) increased by this influx opened K(Ca), leading to closure of Ca(V) and consequent cessation of Ca(2+) influx with resultant relaxation. These processes were repeated spontaneously to cause PCs. H(+) and OH(-) were considered to act as the opener and closer of K(Ca), respectively.
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Affiliation(s)
- Yasumi Uchida
- Japan Foundation for Cardiovascular Research, Funabashi, Japan.
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Oloizia B, Paul RJ. Ca2+ clearance and contractility in vascular smooth muscle: evidence from gene-altered murine models. J Mol Cell Cardiol 2008; 45:347-62. [PMID: 18598701 DOI: 10.1016/j.yjmcc.2008.05.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 05/17/2008] [Accepted: 05/29/2008] [Indexed: 01/15/2023]
Abstract
The central importance of calcium clearance proteins, and their regulators, in the modulation of myocardial contractility and intracellular Ca(2+) concentration ([Ca(2+)](i)) has long been established. Key players identified include the Na(+)-Ca(2+) exchanger, the Na(+)-K(+) ATPase, the sarco(endo)plasmic reticulum Ca(2+)-ATPase and associated phospholamban. Gene-targeted and transgenic murine models have been critical in the elucidation of their function. The study of these proteins in the regulation of contractile parameters in vascular smooth muscle, on the other hand, is less well studied. More recently, gene-targeted and transgenic models have expanded our knowledge of Ca(2+) clearance proteins and their role in both tonic and phasic smooth muscle contractility. In this review, we will briefly treat the mechanisms which underlie Ca(2+) clearance in smooth muscle. These will be addressed in light of studies using gene-modified mouse models, the results of which will be compared and contrasted with those in the cardiomyocyte. The recently identified human mutations in phospholamban, which lead to dilated cardiomyopathy, are also present in vascular and other smooth muscle. Given the importance of these Ca(2+) clearance systems to modulation of smooth muscle, it is likely that mutations will also lead to smooth muscle pathology.
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Affiliation(s)
- Brian Oloizia
- Department of Molecular and Cellular Physiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0576, USA
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